Chain Tensioner for Roller Blind

Abstract

The locking tensioner comprises first and second elongate arms connected by a bridge. The distal end of the second arm has a tongue. The distal end of the first arm has a head with an aperture dimensioned to receive a chain therethrough, the head further having a slot dimensioned to releasably receive the tongue within the aperture. The second arm is pivotable relative to the first arm between a locked and an unlocked configuration. In the unlocked configuration, the tongue is disposed in the aperture to permit the chain to move through the aperture. In the locked configuration, the tongue applies a shear force between the chain and the head to restrict the movement of the chain. The bridge biases the first and second arms towards the locked configuration.

I claim: 
     
         1 . A locking tensioner for a roller blind, the roller blind of the type having a roller and a chain or cord to impart rotational movement to the roller, the locking tensioner comprising:
 first and second elongate arms connected at a first end by a bridge, each of the first and second arms having a longitudinal axis and a distal second end,
 the distal end of the second arm having an outwardly extending tongue generally aligned with the longitudinal axis of said second arm, 
 the distal end of the first arm having a head with an aperture dimensioned to receive the chain or chord therethrough, the head further having a slot dimensioned to releasably receive the tongue to permit the tongue to be received within the aperture, 
 the second arm pivotable relative to the first arm between a locked and an unlocked configuration, when in the unlocked configuration the tongue is disposed in the aperture to permit the chain or cord to move through the aperture, when in the locked configuration the tongue applying a shear force between the chain or cord and the head to restrict the movement of the chain or cord through the aperture, 
 the bridge biasing the first and second arms toward the locked configuration. 
   
     
     
         2 . The locking tensioner as claimed in  claim 1  wherein the head generally includes a pair of loop members, the loop members aligned with the longitudinal axis of the first arm and spaced apart to define the slot therebetween. 
     
     
         3 . The locking tensioner as claimed in  claim 2  wherein the tongue is dimensioned to be slidably received within the slot between the loop members. 
     
     
         4 . The locking tensioner as claimed in  claim 3  wherein the chain includes spaced apart beads, the width of the tongue dimensioned to fit between adjacent beads of the chain. 
     
     
         5 . The locking tensioner as claimed in  claim 4  wherein the tongue has an anterior tip, in the locked configuration the tip is disposed within the slot and between the loop members. 
     
     
         6 . The locking tensioner as claimed in  claim 1  wherein each of the first and second arms have an opening for the passage of a first fastener therethrough, the second arm generally aligned and generally overlying the first arm when the locking tensioner is in the unlocked configuration and permitting the first fastener to be received through the respective openings in first and second arms to secure the locking tensioner to a window frame or wall. 
     
     
         7 . The locking tensioner as claimed in  claim 5 , wherein the tongue is arcuate with a concave surface that generally conforms to the curvature of the aperture. 
     
     
         8 . The locking tensioner as claimed in  claim 7  wherein, when in said unlocked configuration, the tongue is fully received within the head such that the concave surface of the tongue is generally aligned with the interior surface of the aperture so that the tongue does not interfere with the movement of the chain or cord through the aperture. 
     
     
         9 . The locking tensioner as claimed in  claim 7 , wherein the distal end of the first arm further includes an attachment portion aligned with the longitudinal axis of the first arm, the attachment portion having a hole or slot therein for the passage of a second fastener therethrough for securing the locking tensioner to a window frame or wall. 
     
     
         10 . A locking tensioner for a roller blind, the roller blind of the type having a roller and a chain or cord to impart rotational movement to the roller, the locking tensioner comprising:
 first and second elongate arms, each connected at a first end by a bridge, each of the first and second arms having a longitudinal axis and a distal second end,
 the distal end of the second arm having an outwardly extending tongue generally aligned with the longitudinal axis of said second arm, 
 the distal end of the first arm having a head with an aperture having a generally arcuate interior surface dimensioned to receive the chain or chord therethrough, the head further having a slot dimensioned to releasably receive the tongue to permit the tongue to be received within the aperture, 
 the second arm pivotable relative to the first arm between a locked and an unlocked configuration, when in the unlocked configuration the tongue disposed in the aperture permitting the chain or cord to move through the aperture, when in the locked configuration the tongue applying a shear force between the chain or cord and the head to limit the movement of the chain or cord through the aperture, 
 the bridge biasing the first and second arms toward the locked configuration, and 
 the tongue being arcuate with a concave surface that generally conforms to the curvature of the interior surface of the aperture. 
   
     
     
         11 . The locking tensioner as claimed in  claim 10 , wherein when the locking tensioner is secured to a surface, the tongue is fully received within the head such that the concave surface of the tongue is generally aligned with the interior surface of the aperture so that the tongue does not interfere with the movement of the chain or cord through the aperture. 
     
     
         12 . The locking tensioner as claimed in  claim 10 , wherein each of the first and second arms have an opening for the passage of a fastener therethrough, the second arm generally aligned and generally overlying the first arm when the locking tensioner is in the unlocked configuration and permitting the fastener to be received through the respective openings in said first and second arms to secure the locking tensioner to a window frame or wall. 
     
     
         13 . The locking tensioner as claimed in  claim 10 , wherein the head includes a pair of loop members, the loop members aligned with the longitudinal axis of the first arm and spaced apart to define the slot therebetween. 
     
     
         14 . The locking tensioner as claimed in  claim 13  wherein the tongue is dimensioned to be slidably received within the slot between the loop members. 
     
     
         15 . The locking tensioner as claimed in  claim 10  wherein the chain includes spaced apart beads, the width of the tongue dimensioned to fit between adjacent beads of the chain. 
     
     
         16 . The locking tensioner as claimed in  claim 14  wherein the tongue has an anterior tip, wherein in the locked configuration, the tip is disposed within the slot and between the loop members.